Left 4 Dead 2 is a cooperative first-person shooter developed and published by Valve Corporation. Released in 2009, it follows four survivors battling through zombie-infested campaigns across the American South. The game emphasizes teamwork, featuring dynamic AI known as the “Director” that changes enemy placement and difficulty in real time. With multiple modes, melee weapons, and iconic Special Infected enemies, it remains one of the most popular co-op multiplayer PC games.